This program project is a multidisciplinary approach to study the prevalence, natural history and pathogenesis of human papillomavirus (HPV) infections of the genital tract. Recent evidence suggests that infection with the genital HPV types, i.e., 6,11,16,18,31,33 etc., is widespread in the population and that asymptomatic infection with these viruses may be a common occurrence of childhood. Four projects are proposed: The first project focuses on perinatal and childhood transmission of HPVs. Women will be monitored throughout pregnancy and during the post partum period. The babies will be monitored at birth and during regularly scheduled infant/childhood exams. In addition partners of the mothers and other siblings in the family will be studied. Assessment of HPV infection will be made by both detection of viral DNA, and by serologic assays. The second project focuses on the rate of acquisition and the risk factors associated with HPV infection in college women who are initiating sexual activity. The third project is to characterize the humoral immune response to HPV infection. Using newly developed serologic assays the prevalence of HPV infection will be determined in the above populations. The patterns of antibody response to various viral antigens will be investigated and correlated with the clinical findings. The fourth project focuses on the pathogenesis of HPV infection by investigating at the molecular and cellular level the nature of the interaction between HPVs and various types of epithelial cells to better understand the in vivo behavior of the virus. The projects will be supported by four cores which will analyze samples for HPV DNA (by PCR, Southern blot and Virapap), perform cytologic and histologic analyses, provide data management and biostatistical analysis, and coordinate administrative functions.